Have they checked the lining of your uterus I think it is? Sometimes that can be too thick or not thick enough and is the reason behind not being able to make it stick. There's meds to help fix this.
Hope all goes well with the rounding up of your pregnancy and you can make a start again soon.
That's a great start! It's so hard to lose weight. I've been super lucky and lost 11.4 kg so far with this pregnancy, not because of vomiting or anything, bub just must think I'm too fat and is trying to make some room down there lol.
Take care xx